Spark Timing…..am I being a p*$$y

[HPLouis]

So, my car’s got the ported blower, 2.8 pulley and I’ve datalogged 12.8lbs of boost at the highest but it’s usually around 12.2 to 12.5lbs, JLT intake, BA 2600 MAF, 60lbs injectors, BAP, head cooling mod, 170 degree t-stat, Billetflow throttle body, TR6IX plugs, long tubes, no cats, no EGR, Bassani catback and SCT tune from Greg at RET.

Here is the sheet:

My wideband shows 10.2 to 10.8 A/F at WOT but I’m worried about timing. My IAT’s can show 100 degrees or 148 and the timing at WOT is still a rock solid 23 degrees. The car usually sits around 120 degrees IAT but I’ve seen as high as 148 degrees. Now, I don’t hear any detonation and I don’t see any black smoke out the exhaust. The plugs aren’t broken or burnt when I check them but, I’ve been reading that 23 degrees is too high for these cars.

I have the tune file and I looked at it with my Pro Racer Package and the timing at the Borderline Knock Table is locked at 23degrees from 4000rpms and up. Also, the spark retard for air change temp practically disabled. It starts pulling timing at 174 degrees.

I emailed Greg and he said that the tune is fine and that’s what he uses on California’s 91 octane and I should be safe on 93 and not to worry, he’s been tuning these cars for 20 years. I also Google’d him and I haven’t read one complain but the timing still scares me. The car drives nice and he even tuned out a lot of the PPRV hesitation and the tune passes NY inspection with no cats and EGR.

What are you guys running? Anyone else running 23 degrees on pump gas and doing OK? Should I drop the timing down to 19-20 or just relax and enjoy the ride?

Thanks for your time everyone.


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[2003RedfireVert]

My pump gas tune with my ported Eaton only saw 19 degrees and the IAT retard started at 140. I would see temps gets pretty high in the summer.

My 93+torco saw 21 degree.

This was ported Eaton, 2.76 upper, stock thermostat, BAP, 60s, yada yada, dual pass HE. I was around 14-15psi.

 

[HPLouis]

My pump gas tune with my ported Eaton only saw 19 degrees and the IAT retard started at 140. I would see temps gets pretty high in the summer.

My 93+torco saw 21 degree.

This was ported Eaton, 2.76 upper, stock thermostat, BAP, 60s, yada yada, dual pass HE. I was around 14-15psi.

That’s where I started seeing the 140, 148 degrees etc., in the hot August days in the middle of summer. I was datalogging in the heat to check the car out and it went strong in the heat, no timing pulled, no detonation, no discolored plugs, etc. It still did 23 degrees of timing and I didn’t hear a thing. Now, I will say this, the car never goes above 190 for engine coolant temp, no matter how hot it is outside, so that thermostat and tune settings for the fan are rock solid.


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[2003RedfireVert]

My car made 470w *before* the port work. I was close to 500w on that tune.

 

[2003RedfireVert]

It's probably fine. Your tuner has probably tuned quite a few of these cars so if he is comfortable, the plugs read fine, and you aren't seeing any detonation I wouldn't worry about it. Throw in some Torco or Octnanium if you want some peace of mind.

 

[01yellercobra]

On my eaton set up I ran 19 degrees at WOT. I left the timing retard at whatever the stock levels were. It was a stock eaton with a 2.8 upper though. I think it made about the same boost.

Overall Greg is good with these cars. I say stop over thinking things and enjoy the car.

 

[ITSTOCK]

23 is useless anyway, not sure why he would run timing that high. It’s a zero sum game, or could be bad.

Basically, that rich and that much timing with basically no retard table on 91/93, your tune sucks.

 

[smashedheadcat]

If you have the PRP, just pull a few degrees out, adjust the IAT modifier to pull timing sooner and save it as a new file. Thats the beauty of the PRP.

I doubt you’ll lose much in the name of performance, but you can enjoy your car without worrying about hurting anything. You can always go back to Greg’s tune if you want.

With all that said, Greg is top notch.

 

[HPLouis]

If you have the PRP, just pull a few degrees out, adjust the IAT modifier to pull timing sooner and save it as a new file. Thats the beauty of the PRP.

I doubt you’ll lose much in the name of performance, but you can enjoy your car without worrying about hurting anything. You can always go back to Greg’s tune if you want.

With all that said, Greg is top notch.

I was thinking of that. I can lower the borderline knock table to 22 degrees from 4000rpms and up. Then I can change the IAT modifier back to stock. That'll give me 22 degrees at 100 and below IAT temps (and the IATs are never that low). Then at 125 or so (this is where it's usually at), it would be 20 degrees and then it goes down to 18 degrees at 150 and then less and less timing as the IATs get higher.

 

[HPLouis]

23 is useless anyway, not sure why he would run timing that high. It’s a zero sum game, or could be bad.

Basically, that rich and that much timing with basically no retard table on 91/93, your tune sucks.

Let me correct myself. I just checked my old logs and the display shows richer A/F ratios as compared to the LAMBDA datalogs.

In LAMBDA, I have
2500-3000rpms: LAMBDA .718 to .766
3000-4000rpms: LAMBDA .714 to .762
4000-5000rpms: LAMBDA .73 to .78
5000-6000rpms: LAMBDA .69 to .74
6000-6500rpms: LAMBDA .71 to .75

 

[q6543]

Throw some fresh plugs in it, make a good pass with some real duration.

Pull them, cut them and see what's going on in there.

 

[HPLouis]

OK, here's the changes I made:
spark........4000rpms............5000rpms...........6000rpms
IAT0............21degs...............22degs...............22degs
IAT125.......19.5degs.............20.3degs...............20.1degs
IAT150.......18degs................18.6degs............18.2degs

As the temps get higher, more timing gets pulled down.

 

[ITSTOCK]

Let me correct myself. I just checked my old logs and the display shows richer A/F ratios as compared to the LAMBDA datalogs.

In LAMBDA, I have
2500-3000rpms: LAMBDA .718 to .766
3000-4000rpms: LAMBDA .714 to .762
4000-5000rpms: LAMBDA .73 to .78
5000-6000rpms: LAMBDA .69 to .74
6000-6500rpms: LAMBDA .71 to .75

I don't know, you're still way too rich and in the same stated range. What fuel do you actually run?

Your new timing for MAT is much better.

 

[HPLouis]

I don't know, you're still way too rich and in the same stated range. What fuel do you actually run?

Your new timing for MAT is much better.

I run 93 octane and you’re right. It’s still too rich. I need to work the MAF transfer function and try to get to 0.789 which is what I have on the base fuel table.

 

[44shelby]

Go to a track and bring some plugs with you as well as a hacksaw. WITH ZERO MILES AND NO IDLE TIME on a brand new set of plugs make a pass and kill it. coast to the return road and pull the plugs on the drivers side. Cut the threads off and read the plug. Just because the rule of thumb is one thing doesn't really mean it applies for every car. Id start with his tune and see what it the plugs look like. If the plugs are peppered then its detonating.

 

[44shelby]

Another option is just buy a case of boostane. Half a can per fill up is cheap insurance and keeps things inline when running pump gas.

 

[HPLouis]

Go to a track and bring some plugs with you as well as a hacksaw. WITH ZERO MILES AND NO IDLE TIME on a brand new set of plugs make a pass and kill it. coast to the return road and pull the plugs on the drivers side. Cut the threads off and read the plug. Just because the rule of thumb is one thing doesn't really mean it applies for every car. Id start with his tune and see what it the plugs look like. If the plugs are peppered then its detonating.

I spoke to the prior owner and he was telling me I'm being too paranoid about this. He ran the tune and checked plugs and didn't see any detonation or problems either. I just would rather play it safe and drop some timing.

 

[44shelby]

I would put it all back and go see for yourself... and if it checks out then it it checks out. At that point I would run a half can of boostane in there just as my safety net on everything and it works as a fuel stabilizer as well.

 

[HPLouis]

I would put it all back and go see for yourself... and if it checks out then it it checks out. At that point I would run a half can of boostane in there just as my safety net on everything and it works as a fuel stabilizer as well.

Perfect. Thanks. There is a dyno close by so I'll try it there. The track is too far.

 

[44shelby]

Perfect. Thanks. There is a dyno close by so I'll try it there. The track is too far.

If you got a stretch of road that aint busy with some place to pull over it works just as good... All it takes is a 1-4 gear pull. Cheapest way to go. Its hard to get that in the city though.